feat: harden atoms-nexst against review findings (37 items)

Second review pass covering security, performance, admin tooling and the
public/room flows. All HIGH and MEDIUM findings from the audit are resolved;
nothing in this commit changes the visible feature set.

Authentication & session security
- CSP is now set on the request headers in the proxy, which is what Next.js
  uses to derive the render nonce, so the nonce is effective.
- 2FA: an already-enabled user cannot re-enroll, the setup endpoint is
  rate-limited per account, and confirmed codes are persisted so the second
  secret no longer silently never applies.
- Password reset revokes the ticket, authTicket and all personal access
  tokens, and bumps the token version so existing sessions die. The same
  revocation is now wired into the staff-side password reset.
- /reset and /verify return a stable error code instead of raw text; the
  mail lookups are ordered by id so duplicates cannot vary between runs.
- Resending the verification mail gets a per-address cooldown on top of the
  per-user limit.
- Issue API tokens with the narrower radio/ticket ability set instead of "*".

Authorization & input handling
- Mid-rank staff can no longer keep dynamically granted non-view admin.*
  permissions: existing grants are revoked by migration and the grant lookup
  is restricted to "%.view". Rank guards use the dynamic super-admin check.
- Alerting a user is permission-checked and audited like the other tools.
- Material mutations (giveCredits/giveDuckets/giveDiamonds, the admin user
  actions route, bulk user actions) are capped and rank-guarded, and bulk
  ids are bounded.
- updateRoom / updateRoomItem write through a field allowlist, and items
  may only be edited through their own room.
- Classnames reaching the filesystem are validated before use so a crafted
  value cannot escape the asset directories.
- The word filter now also covers offline mails, guild forum threads and
  replies, and user mottos.
- Media uploads are validated by magic bytes, /api/media requires the page
  edit permission, APP_URL must be configured once mail is enabled, and the
  diagnostics error route checks the fetch site header.

Admin tooling
- Secret settings render masked and cannot be overwritten with a blank or
  an arbitrary raw key; radio credentials are new password inputs.
- Commandocentrum balance changes are audited.
- Admin list pagination reads the caller's per-page instead of the max, and
  the log exporter caps offset and search length.

Performance
- Catalog translations are cached per module, with a cheap revision hash;
  the public online count uses a stale window instead of hammering the DB.
- The cache warmup now primes the payload the home route actually reads.
- TopHeader batches its queries into one round trip, and LCP avatars load
  eagerly.
- motion/react and sonner are no longer part of the root layout; the nav
  dropdown and mobile nav panels are lazy client chunks. Anonymous visitors
  again get the navigation chrome, and public pages get an edge cacheable
  response.

Accessibility
- Nested <main> elements in phase pages became <section>; the page entrance
  and route progress animations are pure CSS that respect reduced motion.

src/lib/permissions.ts

@@ -99,6 +99,28 @@ export const loadUserPermissions = cache(async function loadUserPermissions(
 	}
 });
 
+/**
+ * Highest rank the hotel currently has — i.e. who the dynamic owner is.
+ * Rank comparisons ("can this staff member act on that user") must never be
+ * hard-coded to a number, because hotels disagree on their top rank.
+ * Memoised per request so several rank guards in one action cost one query.
+ */
+export const getHighestRank = cache(async (): Promise<number | null> => {
+	const rows = await queryRows<{
+		highest_rank: number | bigint | null;
+	}>(sql`
+        SELECT COALESCE(
+          (
+            SELECT MAX(u.\`rank\`)
+            FROM users u
+            INNER JOIN permission_ranks pr ON pr.id = u.\`rank\`
+          ),
+          (SELECT MAX(id) FROM permission_ranks)
+        ) AS highest_rank
+      `);
+	return rows[0]?.highest_rank == null ? null : Number(rows[0].highest_rank);
+});
+
 const getCurrentAuthorizationState = cache(async (userId: number) =>
 	resolveAuthorizationState(userId, {
 		user: {
@@ -115,26 +137,7 @@ const getCurrentAuthorizationState = cache(async (userId: number) =>
 				return row ?? null;
 			},
 		},
-		highestRank: async () => {
-			// Prefer the highest rank actually held by a user. Unused high IDs in
-			// permission_ranks (common on Habbo DBs) would otherwise lock the real
-			// owner out of super-admin / permissions management.
-			const rows = await queryRows<{
-				highest_rank: number | bigint | null;
-			}>(sql`
-        SELECT COALESCE(
-          (
-            SELECT MAX(u.\`rank\`)
-            FROM users u
-            INNER JOIN permission_ranks pr ON pr.id = u.\`rank\`
-          ),
-          (SELECT MAX(id) FROM permission_ranks)
-        ) AS highest_rank
-      `);
-			return rows[0]?.highest_rank == null
-				? null
-				: Number(rows[0].highest_rank);
-		},
+		highestRank: async () => getHighestRank(),
 	}),
 );